Perforated record sensing device



Aug. 8, 1950 J. M. CUNNINGHAM PERFORATED RECORD SENSING DEVICE Filed Aug. 25, 1947v Patented Aug. 8, 1950 2,517,984 PERFORATED RECORD sENsrNG DEVICE James M. Cunningham, Endicott, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application August 25, 1947, Serial No. 770,349

1 claim. (c1. zas- 6111) I This invention relates to devices for sensing perforations in record cards and more particularly to devices for sensing such designations while the record cards are in motion through the card feeding mechanism of well known accounting and statistical machines.

' The principal object of the invention is to provide an improved sensing device of the type wherein the sensing of a perforation effects closure of contacts for controlling machine operation. It is desirable to provide as long a contact closure period as possible in order to insure ample time for the operation of the controlled mechanism. Generally the period of such closure has been determined by the length of the perforation in the card and by the rate of movement of the card.

The present invention contemplates a structure in which a sensing element in the form of a star wheel is rotatably mounted on the end of a lever and rests upon a record to traverse a perforated column thereof. Normally, two points ofthe star wheel rest on the card surface and, as a hole arrives and passes beneath the near point, it will roll into the hole, allowing the center of the wheel to drop, thereby rocking the supporting lever and actuating a pair of contacts. Continued advance of the card will cause the trailing edges of the hole to engage the entered point and turn the star Wheel and ultimately cam the point out of the hole leaving the wheel advance one point.

Where the holes sensed follow one another in close proximity, as where they are spaced a distance equal to the pitch of the teeth or points of the star wheel, the wheel will shift bodily upon sensing the rst hole and will thereafter simply roll from such hole to the next without shifting the center of the wheel and the contacts will accordingly remain in their actuated position as long as the succession of closely spaced holes continues.

Other objects of the invention will be pointed out in the following description and claim and illustrated in the accompanying drawings, which disclose, by Way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle,

In the drawings:

Fig. 1 is a detail view of the improved sensing device shown in relation to a perforated record with the card sensing station wheel riding on the imperforate portion of the card.

Fig. 2 is a position view of the parts as a point of the Wheel is entering a perforation.

Fig. 3 is a further position View of the parts after a point of the wheel is fully entered in a perforation.

Fig. 4 is a still further position view of the parts as the entered point is engaged by the trailing edge of a perforation and cammed out of the perforation.

Fig. V5 is a detail showing the wheel being traversed by closely spaced holes.

Referring to the drawing, the record card feeding mechanism is -diagrammatically represented by a pair of feeding rollers 9 which advance record card I0 toward the left with a continuous movement across a supporting plate II. The card I0 which is the well known I. B. M. record card has perforations I2 arranged in the usual columns and rows according to the data their location represents.

In line with each column of perforations I2 is a sensing element in the'form of a five pointed star wheel I3 which is freely rotatable on a pin I4 carried on the free end of a lever I5 freely fulcrumed at I6. An upper edge of lever I5 abuts a plunger I1 vertically slidable in a support I8 and a contact wire or blade I9 bears upon the upper end of plunger I'I to provide a slight spring bias urging wheel I3 against the surface of the card I0.

As rollers 9 propel the card beneath wheel I 3, a pair of adjacent points slide along the surface in the position of Fig. 1 to hold plunger I1 in its upper position against the tension of contact spring wire I9. As a hole l2 moves under the nearer point of wheel I3, tension of spring wire I 9 will cause the wheel to turn with the one point entering hole I2 as shown in Fig. 2 so that wire I El makes contact with stationary contact element 20 to complete an electrical circuit to energize well known devices such as printing or accumulatingr magnets in accordance with the particular type of accounting or statistical machine to which the invention may be applied.

As the card continues to advance, the perforation as it traverses the entered point, enables further penetration until the lower edge of lever I5 contacts the card surface as shown in Fig. 3.

Thereafter, the trailing edge of the entered hole I2 will engage the edge of the entered point of Wheel I3, cam it out of the hole as indicated in Fig. 4 where the point is partly ejected, and the parts are in position to open contacts I9, 20 upon further movement of the card which will return the elements to the position of Fig. 1.

With Fig. 2 representing the position of the card at the instant of closure of contacts I9, 20

and Fig. 4 representing the instant of reopening measurable in terms of card travel by the distance a point on the card travels from the position of Fig. 2 to that of Fig. 4. For the propor tions of the parts illustrated, this distance is a little less than one and a half times the length of hole I2.

Wheel I3 offers very slight resistance to rotation so that the frictional resistance between the edge'of a part and the trailing edge of the card holes is only as much as is required to overcome the light tension of the contact wire I9.

In Fig. 5 is shown a section of a `card in which holes I2 are more closely spaced than in Figs. 1 to 4 with the distance between like points being such that as a point of wheel I3 rolls out of one hole the following point will roll into the next and lever I5 will remain in its lower position. Thus fora succession of such closer spaced holes, contacts I9, 20 lwill close when the rst hole is encountered and will not open until the last in the series passes the wheel so that the duration of contact closure is measured by the number of successive holes passing the wheel.

The construction of a record sensing device as, disclosed has particular Vnovelty in the fact that the record card Il! may move in either direction past wheel I3 and the points will coact of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its 'operation may be made by those skilled in the art without departing from the spirit of the f invention. It is the intention, therefore, to be `lilrtit'ed 'only as indicated by the scope vof the following claim:

What is claimed is: i A sensing device for a perforated record card comprising a lever having a pivot, contacts operated by said lever, a star wheel freely rotatable on the lever at a point remote from said pivot, said wheel having ve tapered teeth, means for moving a perforated record past said ,-wheel, resilient means acting onl the lever to urge the wheel into engagement with the record so that a pair of adjacent teeth of the star wheel contact the record, the movement of a perforation past said pair of teeth causing one of them to rock into the perforation and also causing rocking of the lever to operate the contacts, said perforation having a dimension in the direction of its travel, at least one and a half times the amount required to enable the tooth to rock therein, whereby continued movement of the card will be effected without accompanying movement of the tooth until the trailing edge of the perforation has advanced to engage the `tooth whereuponsaid trailing edge will rotate the wheel and raise it out of the perforation with accompanying rocking of the lever to return the contacts te their initial unoperated condition, whereby the period of operation of the contacts is measured by the extent of movement of the card required t rotate thel wheel one tooth space. Y

JAMES M.r CUNNINGHAM.A

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Austria Oct. 10 1923 

